Plimsoll Line

The Plimsoll line, also known as the International Load Line or simply the waterline, is a marking on a ship's hull which indicates the vessel's draft at a range of allowable load limits. It is named for the Hon. Samuel Plimsoll MP (1824–1898), a British Member of Parliament and social reformer who was an early campaigner for the imposition of a legal requirement for merchant ships to be so marked.